Bug#520251: pbuilder: Pbuilder does not umount bindmounts when ssh connection dies

[Junichi Uekawa]

I think I saw a duplicate bugreport similar to this. Can you merge?

At Wed, 18 Mar 2009 12:46:18 +0100,
Stefan Fritsch wrote:
> 
> Package: pbuilder
> Version: 0.181
> Severity: important
> 
> When pbuilder is executed over ssh and the ssh connection dies, it won't
> umount bind mounts and won't clean up the build dir. Unfortunately,
> cowbuilder WILL cleanup the build dir, wiping all bind mounts. The
> execution order is like this:
> 
> ssh -> sudo -> cowbuilder -> pbuilder
> 
> Because of the sudo, the SIGHUP will not be delivered to pbuilder.
> However, pbuilder will get SIGPIPE when writing to stdout or stderr.
> In addition, even when SIGPIPE is ignored, a write to stdout will give
> EPIPE, which causes echo to return with an error.
> 
> Therefore, you
> 
> - need to catch sigpipe in addition to sighup
> - need to ignore sigpipe and sighup in the cleanup handler
> - need to set +x in the cleanup handler to avoid exiting just
>   because echo returns an error.
> 
> The attached patch works for me but I have only edited
> pbuilder-buildpackage and not the other commands.